Sjon7283, I'm afraid you have to return/exchange the DT Swiss axle you got. brmeyer135, is right.

The E-thru is the one needed for the dropouts that come with the 256 frame, and has an end bolt.
While the X12, based on syntace design, expects a thread integrated in the dropout.

Hello Flyxii, thank you for coming here, do you plan to provide thru-axle endurance/road frames for disc brakes in the future?

Back in June, when ordering my 256 frame, I thought PF30 is the new standard, and took this format.
Then I installed the stock SRAM PF30 that comes with the XX1 groupset.

So far so, good. No creeks or any noise, and without the need of loctite.
Spinning the pedals by hand - without the chain on - was far from smooth, but ok.

Things started to get wrong after the first real ride in the mud.
The bearings were immediately contaminated.
Spinning was sticky, and the bearings made a noise like there was sand in them.

I took the bearings out, cleaned them. And packed them with grease.
If you wonder. They were pre-loaded correctly and I don't pressure wash the bike.

Unfortunately SRAM's BB looks to be designed either for dry conditions only. Or as disposable gear you discard after a race.
A the next wet ride, the bearing were making again the scraping noise and the spin seriously degraded.
It may be a little mental-thing(like many on a bike), but having a resistance when pedalling was depressing.

So I started to look at alternative options.
And found bbinfinite.com

I liked the design immediately, and ordered one.
Mounting it was easy, and wow... what a difference!
The spin was so smooth that I made this comparison video:


Now, after a few weeks of very wet/muddy rides(see the attached picture of a soft one).
The BBinfinite is now making a light noise too(non-drive bearing).
But it keeps spinning like in the video.
Nothing compared to SRAM's noise and friction.

I returned the BB to SRAM(through bike24.com), explaining the design issue for wet rides.
They were very kind, and returned me a new BB.
Unfortunately without any word or explanation, so I guess nothing will change on SRAM's side.

Good choice, the 256 frame is great fun to ride.

Since you are still in doubt. One of the things I'm most happy is the 1X set.
I took the rather expensive XX1, but there are clearly alternative options.

Hi Vipassana, are you happy with the IP-SP7 seatpost?

Is it easy to setup to the right angle?
And does it keep it well?

Not a good news, for all of us.
Did you see it coming, or you saw the wear all of a sudden?

Sjon7283, I took hookless rims.
The external width is 30mm, there are thinner and lighter rims for XC, I think, but I preferred them more robust.

The front wheel has a 123 project hub(for a Lefty fork) and is 680g.
The rear wheel has a Hope Pro V2 Evo(for an XX1 cassette) and is 856g.
Laced with their Pillar aero spoke PSR X-TRA 1420, 32 per wheel.

They say tubeless ready, so it means you need to put a tape(Stan or other) over the spoke holes.
If you want to go tubeless with them. What I did without any problem.